I'm going to assume that you are stitching manually in photoshop.
Here is a four image example, you could do the same for a 8 image stitch.
You could just chop each frame (A B C D) in half. So then you would have,
A1, A2, B1, B2, C1, C2, D1, D2
Then blend,
A2+B1
B2+C1
C2+D1
Then just join all the images together in one file,
A1, A2+B1, B2+C1, C2+D1, D2
So you save memory when doing the manual blending, and the last step is just pasting the final components together in one image (with no need to blend).